Prior explosion vents are known for preventing pressure buildups within pressurized systems, such as pressure buildups caused by explosions or the like. The systems may include one or more chambers where pressure buildups can occur. These explosion vents are typically installed at multiple locations of a pressurized system for relieving pressure buildup at that location. In the event that the pressure within the system increases beyond a threshold level, the explosion vent will open, relieving the pressure.
In addition to relieving a pressure buildup, the explosion vents are also configured to withstand a vacuum pressure, or back pressure, that occurs inside the chamber during pressure cycling. Thus, these devices must be configured to withstand a back pressure caused by vacuum cycling while also being configured to burst in the forward direction in the event of a pressure buildup.
One type of vent apparatus is in the form of a door that is configured to open in the event that pressure rises above a predetermined level. However, this door type vent apparatus was generally not airtight, which resulted in undesirable air leakage from the pressurized system.
Another type of vent apparatus is in the form of a steel frame structure having plywood or cardboard wall panels secured with fasteners. The fasteners are configured to break at a predetermined high pressure. However, this arrangement withstands substantially the same forward and back pressure burst levels due to the flat nature of the panels and the fasteners.
Yet another vent apparatus is in the form of a sheet metal panel having perforations formed therein. A plastic seal is disposed along one side of the sheet metal to prevent air leaks within the system. The metal sheet includes a domed portion that is configured to withstand the back pressure on the sheet. The predetermined burst pressure in the forward direction is generally determined by the number of perforations and the size of the dome. As pressure increases, the tension in the sheet will cause the sheet to burst at the perforations to relieve the pressure buildup. Thus, this arrangement requires substantially different configurations for the sheet metal panel for different burst ratings, and the manufacturing process for different domed panels requires additional tooling, adding to the cost of manufacturing these different vent apparatuses.
Another vent apparatus can include a metal sheet having multiple domed portions, with a slit extending through the domed portions. The metal sheet withstands inlet pressure by using multiple connectors that are riveted or fastened to the sheet across the slit on the domed portion. The connectors are configured to break at a predetermined pressure. When pressure increases beyond the predetermined level, the connectors will break to allow the sheet to open and for the pressure to be vented. The connectors are fastened to the sheet along the slit, which is located on the domed portions and is coated with an elastomeric seal to prevent leakage. However, this location of the slit and connectors thereon causes the metal material adjacent the slit to undergo a direct loading during pressure cycling, which can reduce the number of cycles that the vent apparatus will function correctly. Moreover, the exposure to the pressurized environment can result in a buildup of debris or other airborne product within the chamber at and around the slit in the domed portions. Furthermore, the installation of the multiple individual connector members is time consuming and increases the costs of manufacture.